Cover latching device



May 22, 1962 R. v. RIMMER ET AL COVER LATCHING DEVICE Filed 001;. 22, 1959 WITNESSES Fig.2.

Fig.5.

ATTORNEY United States Patent 3,035,859 COVER LATCHING DEVICE Robert V. Rimmer and William F. Born, Beaver, Pa., as-

signors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Filed Oct. 22, 1959, Ser. No. 848,001 3 Claims. (Cl. 292-428) This invention relates, generally, to cover latching devices and, more particularly, to latching devices for cabi nets which enclose circuit interrupters such as automatic circuit breakers and manually operable switches that are operable from outside of the cabinets by means of external operating handles.

Mechanical interlocking has been provided in the prior art which normally required that the breaker or switch be open before the cover of the cabinet could be opened. Also, an externally operable cover latch had to be released in order to open the cover. Under certain conditions, it is desirable to provide additional safety fea tures on enclosed circuit interrupters.

An object of this invention is to provide an improved safety latch for the cover of the enclosing cabinet for a circuit interrupter.

A more specific object of the invention is to provide a safety member which cooperates with the cover latch of a cabinet to prevent the unintentional opening of the cover.

A further object of the invention is to provide a gravity actuated safety member for cooperating with the cover latch of a cabinet.

Other objects of the invention will be explained fully hereinafter or will be apparent to those skilled in the art.

In accordance with one embodiment of the invention, a cover latch is pivotally mounted on the side of a cabinet and engages a bracket on the cover to retain the cover closed. A safety member is pivotally attached to the cover latch and swings by gravity to a position in which it engages the cover bracket to prevent release of the cover latch. The safety member must be moved out of engagement with the cover bracket to release the cover latch and open the cover.

For a better understanding of the nature and objects of the invention, reference may be had to the following detailed description, taken in conjunction with the accompanying drawing, in which:

FIGURE 1 is a view, in front elevation, of a cabinet for enclosing a circuit interrupter;

FIG. 2 is a view, in side elevation, of the cabinet shown in FIG. 1;

FIG. 3 is an enlarged view, in side elevation, of the cover latch and cooperating safety member, the latch and the safety member being in the released position;

FIG. 4 is a view, similar to FIG. 3, with the latch and the safety member in the engaged position; and

FIG. 5 is a view, in section, taken along the line V-V in FIG. 4.

Referring to the drawing, and particularly to FIGS. 1 and 2, the structure shown therein comprises a sheet metal cabinet 11 having an openable cover 12 which is hinged at one side of the cabinet 11 by means of hinges 13. The cabinet 11 is normally mounted in a vertical position and may be attached to suitable supporting members (not shown) by means of feet 14 and 15 having openings 16 and 17, respectively, therein.

The cabinet 11 is of a type suitable for enclosing a circuit interrupter (not shown) which may be a manually operable switch of the type described in Patent 2,849,572, issued August 26, 1958, to A. R. Cellerini et al., or the interrupter may be a circuit breaker of the type described in Patent No. 2,047,739, issued July 14, 1936, to H. J. Lingal. An external operating handle 18 is rotatably mounted on the side of the cabinet 11 for operating the circuit interrupter which is mounted inside the cabinet. If desired, the handle 18 may be mounted on the cover 12 of the cabinet. As shown, an indicating plate 19 containing the words on and off is attached to the cover 12 to indicate whether the interrupter is closed or opened.

As explained hereinbefore, mechanical interlocking may be provided to normally prevent the cover 12 from being opened while the interrupter is in the closed position. In order to secure additional protection against the unauthorized or unintentional opening of the cover 12, a latching device 21 is provided. As shown in FIGS. 3, 4 and 5, the latching device 21 comprises a latch member 22 and a safety member 23 which cooperate with a bracket 24 to retain the cover closed. The bracket 24 is generally of a U-shape comprising two leg portions that are joined by a bight portion, and having feet 25 attached to a flange 26 on the cover 12. The latch member 22 is pivotally mounted on the side of the cabinet 11 by means of a pin 27. As shown in FIG. 4, a projection 28 on the latch member 22 engages the bracket 24 when the latch is closed to prevent opening of the cover 12. The safety member 23 is pivotally attached to the latch member 22 by means of a shoulder rivet 29'. The safety member 23 is free to swing about its pivot point 29 and, as shown in FIG. 4, is actuated by gravity to a position in which the lower end of the member 23 will engage the bracket 24 to prevent release of the latch 22 to thereby prevent opening of the cover 12.

As shown, the safety member 23 is disposed within the confines of the bracket 24 and it is necessary to insert a screwdriver, or other tool, between the bracket 24 and the flange 26 of the cover to move the member 23 to the position shown in FIG. 3, in which position it is disengaged from the bracket 24, thereby permitting the latch 22 to be released from the cover 12. Thus, it will be seen that the latch 22 cannot be released without first moving the safety member 23 about its pivot point 29.

When the cover 12 is closed, the latch 22 is raised by a torsion spring 30 to the position shown in FIG. 4

- in which position the shoulder 28 engages the bracket 24 to retain the cover closed. When the latch 22 is raised to the position shown in FIG. 4, the member 23 will swing by gravity to the position shown in FIG. 4, thereby preventing the latch 22 from being released without first moving the member 23 about its pivot point 29. A stop pin 31 is mounted on the side of the cabinet to limit travel of the latch member 22 about its pivot pin 27. One arm of the spring 30 engages the pin 31 and the other arm engages a projection 32 on the latch member 22. The spring is wrapped around the pin 27, thereby biasing the latch member 22 upwardly about its pivot point 27. An opening 33 is provided in the latch member 22 for receiving the hasp of a padlock which may be utilized to lock the cover 12 closed if desired.

From the foregoing description, it is apparent that we have provided an improved simple and effective latching device for the cover of a switch cabinet which latching device prevents the unintentional opening of the cover. Thus, a cabinet is provided having an improved safety feature. The present device may be economically manufactured and installed.

Since numerous changes may be made in the abovedescribed construction, and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

We claim as our invention:

1. A latching device for a cabinet having an openable cover, said latching device comprising a bracket adapted to be mounted on said cover, a latch member adapted to be pivotally mounted on said cabinet for releasably engaging said bracket to latch said cover in the closed position, a safety member pivotally mounted on said latch member and being gravity actuated to a latching position to prevent release of said latch member, said safety member when in latching position being disposed substantially within the confines of said bracket, and said safety member being movable about its pivot to an unlatching position to permit release of said latch member to thereby permit opening of said cover.

2. A latching device for a cabinet having an openable cover, said latching device comprising a generally U- shaped bracket having two leg portions joined by a bight portion and being adapted to be attached to said cover, a latch member adapted to be pivotally mounted on said cabinet for releasably engaging said bracket to latch said cover in the closed position, a safety memberpivotally mounted on said latch member and being gravity actuated to a latching position to prevent release of said latch member, said safety member when in latching position being disposed substantially between said bight portion and said cover, and said safety member being movable about its pivot to an unlatching position to permit release of said latch member to thereby permit opening of said cover.

3. A latching device for a cabinet having an openable cover, said latching device comprising a generally U- shaped bracket having two leg portions joined by a bight portion and being adapted to be mounted on said cover, a latch member adapted to be pivotally mounted on said cabinet for releasably engaging said bracket to latch said cover in the closed position, means biasing said latch member to the latching position, a safety member pivotally mounted on said latch member and being gravity actuated to a latching position to engage said bracket to prevent release of said latch member, said safety member when in latching position being disposed substantially between said leg portions of said generally U-shaped bracket, and said safety member being movable about its pivot to an unlatching position to permit release of said latch member to thereby permit opening of said cover.

References Cited in the file of this patent UNITED STATES PATENTS 377,522 Kester .....-.V... Feb. 7, 1888 481,557 Gagnon et a1 Aug. 30, 1892 758,952 Baxter May 3, 1904 1,155,953 Morrou Oct. 5, 1915 2,167,324 Roberts July 25, 1939 2,326,069 Samzelius Aug. 3, 1943 2,541,890 Schaperkotter et a1 Feb. 13, 1951 FOREIGN PATENTS 1,085,001 France July 21, 1954 

